With regard to a rectifier unit of an on-vehicle charging generator, and specifically, with regard to a full-wave rectifier for rectifying a three-phase AC electric power generated by an armature winding, in order to reduce its power loss, there is proposed a full-wave rectifier comprising a MOSFET (metal oxide semiconductor field-effect transistor).
For example, as a control circuit for causing a MOSFET of a predetermined phase to be conductive or non-conductive, there is known a technology for turning on or off an arm element for rectifying an electric current of the predetermined phase when a voltage of a phase different from the predetermined phase exceeds a threshold value (see, for example, Japanese Patent Laid-open No. 2004-7964).